“Follow the water” has been the mantra of scientists looking for the evidence of life, past or present, beyond our own planet.
Observers of Mars in past centuries were filled with hope that Mars was certainly inhabited by intelligent creatures that were responsible for major canal systems carrying water across the planet. Recent observers have been more restrained, hoping simply to establish that water has been present on Mars—in one form or other—and possibly to gather some evidence of primitive life as well.
Early findings from the plethora of spacecraft that have either orbited or landed on Mars in the recent past suggested shallow seas may have pervaded the planet in the distant past and water may have rushed down gullies in recent times. However, the latest conclusions, based largely on results from one of the newest spacecraft on the scene, the Mars Reconnaissance Orbiter (MRO), are far more cautious (see here for a summary of these findings).
The observations are coming from MRO’s High Resolution Imaging Science Experiment (HiRISE). The improved resolution allows one to see a dinner plate on the surface of Mars, compared to a dinner table obtained from the cameras of previous spacecraft. Some results include:
- gullies that were previously thought to be places where water flowed are now explained by dry flows of loose debris;
- dark streaks running down Martian slopes that were thought by some researchers to be caused by water are instead seen as dry dust avalanches;
- the idea of water slicing through lava flows to form the Athabasca Valles is now questioned because the valleys and sediments deposited there appear to be buried under thick lava flows;
- broad, flat basins thought to once harbor ancient oceans are strewn with meter-sized boulders, hardly consistent with long-lived oceans where the expectation was sand-sized sediments.
Much of this data is consistent with the observations from the rovers Spirit and Opportunity, which reveal very slow rates of erosion. Thus, researchers conclude that “running water could not have been much of a player in the past 3 billion years.”
While there is still much evidence of water in and under the ice caps and, perhaps, under the surface of Mars, the search for water and any possible life will have to be more focused. The researchers’ initial enthusiasm is now more tempered.
We trust that the hype regarding the potential for finding life has not tempered the public’s enthusiasm for exploring Mars. Reasons To Believe applauds such efforts, since they lead to greater understanding and appreciation for God’s creation.